764 - Transcutaneous CO2 Monitoring in Extremely Low Gestational Age Neonates

Publication Number: 764.6779

Kuang Chuen Liu, Comer Children's Hospital at University of Chicago Medical Center, Chicago, IL, United States; Walid Hussain, Comer Children's Hospital at University of Chicago Medical Center, Chicago, IL, United States; Sudhir Sriram, University of Chicago, Chicago, IL, United States

Background: Non-invasive technologies have been used as adjunctive tools for alleviating the burden of invasive measurements. Transcutaneous CO2 monitoring (TcCO2) allows for alleviating blood draw burden to our smallest and most vulnerable patients.

Objective: We sought to compare the amount of blood gas measurements done on extremely low gestational age neonates (ELGANs) with gestational ages < 28 weeks before and after introduction of TcCO2 monitors and creation and implementation of guidelines.

Design/Methods: This is a single-center retrospective study in the neonatal intensive care unit (NICU) at the University of Chicago Comer Children’s Hospital. Our patients included ELGANs (N = 78), requiring invasive and non-invasive ventilatory support with blood gas monitoring. The primary outcome is the amount of blood gas measurements performed on infants in the first two months of life before and after implementation of TcCO2 monitors. Secondary outcomes include the use of antenatal corticosteroids and invasive ventilation. A guideline for TcCO2 monitoring based on the level of ventilation support was also performed. The study was classified into three epochs: Epoch 1 (2019) is prior to the use of TcCO2 monitors (N = 18). Epoch 2 (2023) is after implementing TcCO2 monitors without guidelines (N = 30). Epoch 3 (2024) after implementing TcCO2 monitors with guidelines (N = 30). We expressed our data in means and standard deviations, if normally distributed and in medians and interquartile ranges (IQR), if not normally distributed. We used negative binomial regression models for statistical analysis adjusting for antenatal steroids, gestational age, gender, respiratory support and duration. Statistical significance was set at p-value < 0.05.

Results: Our study population included ELGANs with a mean gestational age of 25 ± 1.4 weeks and birth weight of 737 ± 170 grams. The median number of blood gas measurements in epoch 1 was 29 (IQR 9-44); epoch 2 was 16 (IQR 8-29); epoch 3 was 17 (IQR 10-32). The number of blood gases done in epoch 2 was 38% less (Adjusted incidence rate ratio 0.62, 95% CI 0.46-0.83) and in epoch 3 was 45% less (Adjusted incidence rate ratio 0.55, 95% CI 0.41- 0.74) when compared to epoch 1 (p = 0.001). Blood gas amounts between epoch 2 and 3 was 9% less (Adjusted incidence rate ratio 0.91, 95% CI 0.71-1.18, p = 0.478)

Conclusion(s): 1) When comparing the presence or absence of TcCO2 monitoring, there was a reduction in the number of blood gases drawn.
2) When comparing the presence or absence of TcCO2 guidelines, was no difference in the number of blood gases drawn.

Number of Blood Gases done on ELGANs before and after Implementation of TcCO2 Monitoring
Median number of blood gas measurements. Epoch 1 (2019) had a median of 29 (IQR 9-44); epoch 2 (2023) was 16 (IQR 8-29); epoch 3 (2024) was 17 (IQR 10-32). The number of blood gases done in epoch 2 were 38% less (Adjusted incidence rate ratio 0.62, 95% CI 0.46-0.83) and in epoch 3 were 45% less (Adjusted incidence rate ratio 0.55, 95% CI 0.41- 0.74) when compared to epoch 1 (p=0.001).

Demographics and Results
Table of demographics and results. Data described in median values with interquartile range. All infants were of gestational age <28 weeks. Multivariate analysis performed included adjustment for gestational age, sex, completion of antenatal corticosteroids, and invasive ventilation days. Each variable comparison is reported with p-values, with significance reached at p < 0.05. All comparisons were for epoch 2 and 3 versus epoch 1. The comparison between only epoch 2 and 3 had a p-value of 0.478.

Transcutaneous CO2 monitoring guideline.
Transcutaneous CO2 monitoring guideline implemented between 2023 and 2024. Patients who were eligible for monitoring included any type of positive pressure ventilation. Patients excluded from monitoring were at the provider's discretion based on clinical status, skin integrity, or adhesive intolerance.